Information encoding apparatus, information encoding method, information re-encoding apparatus and information re-encoding method

ABSTRACT

An information encoding apparatus for encoding N pieces of information, the information encoding apparatus includes a scrambling pattern generation section for generating M scrambling patterns (N&gt;M≧1; where M and N are each an integer); a scrambled information generation section for applying, to each of the N pieces of information, one corresponding scrambling pattern among the M scrambling patterns so as to generate N pieces of scrambled information; and an encoded information generation section for supplying the N pieces of scrambled information with N parities, respectively, so as to generate encoded information. Each of at least one of the M scrambling patterns is applied to two or more of the N pieces of information.

This non-provisional application claims priority under 35 U.S.C., §119(a), on patent application No. 2003-106390 filed in Japan on Apr. 10,2003, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information encoding apparatus andmethod for encoding a plurality of pieces of information, and aninformation re-encoding apparatus and method for re-encoding a pluralityof pieces of first encoded information into a plurality of pieces ofsecond encoded information.

2. Description of the Related Art

Recently, a storage capacity of optical discs (e.g., DVDs (DigitalVersatile Discs)) and optomagnetic discs is increased, and the opticaldiscs and the optomagnetic discs are used for recording moving picturesor the like.

FIG. 17 shows a conventional information encoding apparatus 1500.

The information encoding apparatus 1500 includes a storage section 1501,a scrambling section 1502 and a parity generation section 1503. Theinformation encoding apparatus 1500 is included in, for example, anoptical disc recording and reproduction apparatus for encoding aplurality of pieces of information.

The storage section 1501 stores a plurality of pieces of information.

The scrambling section 1502 scrambles the plurality of pieces ofinformation. The plurality of pieces of information are scrambled inorder to provide the optical disc recording and reproduction apparatus,for reproducing the plurality of pieces of information, with stabletracking servo control. The plurality of pieces of information arescrambled by adding a random data stream (hereinafter, referred to as a“scrambling pattern”) to the information.

For example, an optical disc has a plurality of tracks formed therein.Information is recorded on the plurality of tracks. A scrambling patternto be added to the information at a prescribed position on a track isdifferent from a scrambling pattern to be added to the information at adifferent position on the track. In general, different scramblingpatterns are used for information of different error correction units.

The parity generation section 1503 generates a plurality of parities incorrespondence with the plurality of pieces of scrambled information.

The plurality of pieces of scrambled information are respectivelysupplied with the plurality of parities, so that encoded information isgenerated.

The encoded information is recorded on a recording medium such as anoptical disc or the like.

In the case where the information cannot be recorded at a prescribedposition on the track due to a defect at that position, the informationis recorded at a different position on the track. When the informationis recorded at a different position, the scrambling pattern to be addedto the information needs to be changed. Accordingly, the informationneeds to be re-encoded.

FIG. 18 illustrates re-encoding of information.

Hereinafter, a procedure for generating a plurality of pieces ofinformation scrambled with a plurality of scrambling patterns C byre-encoding a plurality of pieces of information scrambled with aplurality of scrambling patterns B by the information encoding apparatus1500.

The scrambling section 1502 de-scrambles the encoded information storedin the storage section 1501. For example, de-scrambling is an operationfor returning scrambled information into the non-scrambled information.De-scrambling, similar to scrambling, is performed by adding ascrambling pattern to the scrambled information. For example,non-scrambled information is generated by adding a scrambling pattern Bto the information scrambled with the scrambling pattern B.

The scrambling section 1502 generates information scrambled with ascrambling pattern C by adding the scrambling pattern C to non-scrambledinformation.

The parity generation section 1503 generates parities. The paritygeneration section 1503 generates re-encoded information by supplyinginformation scrambled with the scrambling pattern C with a parity.

Re-encoding information using the information encoding apparatus 1500 istime-consuming. For example, for performing real-time recording of amoving picture, the recording rate is significantly reduced.

It has been proposed to reduce the information re-encoding time bydividing encoded information into a portion relying on the informationto be recorded on a recording medium and a portion relying on theposition on the recording medium at which the information is to berecorded, processing these portions, and adding these portions togetherwhen recording these portions on the recording medium (for example,Japanese Laid-Open Publication No. 2000-306342).

FIG. 19 shows a structure of an information re-encoding apparatus 1700described in Japanese Laid-Open Publication No. 2000-306342.

The information re-encoding apparatus 1700 includes a first storagesection 1701, a first parity generation section 1702, a patterngeneration section 1703, a second storage section 1704, a second paritygeneration section 1705, and an addition section 1706.

The first storage section 1701 has a plurality of pieces of informationstored thereon. The first parity generation section 1702 generates aplurality of first parities in correspondence with the plurality ofpieces of information.

The plurality of pieces of information are respectively supplied withthe plurality of first parities, so that a plurality of pieces of errorcorrection encoded information are generated. The plurality of pieces oferror correction encoded information are stored in the first storagesection 1701.

The pattern generation section 1703 generates a plurality of scramblingpatterns. The plurality of scrambling patterns are stored in the secondstorage section 1704.

The second parity generation section 1705 generates a plurality ofsecond parities in correspondence with the plurality of scramblingpatterns.

The plurality of scrambling patterns are respectively supplied with theplurality of second parities, so that a plurality of pieces of errorcorrection encoded scrambling patterns are generated. The plurality oferror correction encoded scrambling patterns are stored in the secondstorage section 1704.

The addition section 1706 generates encoded information by adding theplurality of pieces of error correction encoded information and theplurality of error correction encoded scrambling patterns. The encodedinformation is stored in a recording medium (not shown).

The above-described apparatuses have the following problems.

(1) The method of scrambling information to be recorded sector by sectorof the recording medium is time-consuming.

(2) In the case where the information re-encoding time is reduced bydividing encoded information into a portion relying on the informationto be recorded on a recording medium and a portion relying on theposition on the recording medium at which the information is to berecorded, processing these portions, and adding these portions togetherwhen recording these portions on the recording medium, an additionalstorage section for temporarily storing the portion of the encodedinformation relying on the position on the recording medium at which theinformation is to be recorded is required.

(3) In the case where the information cannot be recorded at a prescribedposition on the track and is recorded at a position which is notadjacent to the prescribed position, time is required for re-encodingthe portion of the information relying on the position on the recordingmedium at which the information is to be recorded so that theinformation is recordable at a position which is not adjacent to theprescribed position.

SUMMARY OF THE INVENTION

According to one aspect of the invention, an information encodingapparatus for encoding N pieces of information is provided. Theinformation encoding apparatus includes a scrambling pattern generationsection for generating M scrambling patterns (N>M≧1; where M and N areeach an integer); a scrambled information generation section forapplying, to each of the N pieces of information, one correspondingscrambling pattern among the M scrambling patterns so as to generate Npieces of scrambled information; and an encoded information generationsection for supplying the N pieces of scrambled information with Nparities, respectively, so as to generate encoded information. Each ofat least one of the M scrambling patterns is applied to two or more ofthe N pieces of information.

In one embodiment of the invention, the M is a divisor of N, and thescrambling information generation section applies one correspondingscrambling pattern among the M scrambling patterns to each of the Npieces of information such that the M scrambling patterns are repeatedN/M times, so as to generate the N pieces of scrambled information.

In one embodiment of the invention, the information encoding apparatusfurther includes a first storage section for storing the N pieces ofscrambled information and the N parities in order to supply the N piecesof scrambled information with the N parities.

In one embodiment of the invention, the information encoding apparatusfurther includes a second storage section for storing the M scramblingpatterns.

In one embodiment of the invention, the encoded information generationsection is a division circuit.

In one embodiment of the invention, the encoded information generationsection generates the N parities by erasure correction.

In one embodiment of the invention, N is 32 and M is 1.

According to another aspect of the invention, an information encodingmethod for encoding N pieces of information is provided. The informationencoding method includes the steps of (a) generating M scramblingpatterns (N>M≧1; where M and N are each an integer); (b) applying, toeach of the N pieces of information, one corresponding scramblingpattern among the M scrambling patterns, thereby generating N pieces ofscrambled information; and (c) supplying the N pieces of scrambledinformation with N parities, respectively, thereby generating encodedinformation. Each of at least one of the M scrambling patterns isapplied to two or more of the N pieces of information.

In one embodiment of the invention, the M is a divisor of N, and step(b) includes the step of applying one corresponding scrambling patternamong the M scrambling patterns to each of the N pieces of informationsuch that the M scrambling patterns are repeated N/M times, therebygenerating the N pieces of scrambled information.

In one embodiment of the invention, the information encoding methodfurther includes the step of storing the N pieces of scrambledinformation and the N parities in order to supply the N pieces ofscrambled information with the N parities.

In one embodiment of the invention, the information encoding methodfurther includes the step of storing the M scrambling patterns.

In one embodiment of the invention, step (c) includes the step ofgenerating the N parities by division operation.

In one embodiment of the invention, step (c) includes the step ofgenerating the N parities by erasure correction.

In one embodiment of the invention, N is 32 and M is 1.

According to still another aspect of the invention, the informationre-encoding apparatus for re-encoding a plurality of pieces of firstencoded information into a plurality of pieces of second encodedinformation is provided. The plurality of pieces of first encodedinformation include a plurality of first scrambled information scrambledby performing an arithmetic operation on a plurality of first scramblingpatterns with respect to a plurality of pieces of information by a firstmethod. The plurality of pieces of second encoded information include aplurality of pieces of second scrambled information scrambled byperforming an arithmetic operation on a plurality of second scramblingpatterns with respect to the plurality of pieces of information by thefirst method, and a plurality of second parities. The informationre-encoding apparatus includes a third scrambling pattern generationsection for performing an arithmetic operation on the plurality of firstscrambling patterns with respect to the plurality of second scramblingpatterns by a second method, so as to generate a plurality of thirdscrambling patterns; a scrambled information generation section forperforming an arithmetic operation on the plurality of third scramblingpatterns with respect to the plurality of pieces of first scrambledinformation by the first method, so as to generate the plurality ofpieces of second scrambled information; and an encoded informationgeneration section for supplying the plurality of pieces of secondscrambled information with the plurality of second parities, so as togenerate the plurality of pieces of second encoded information. Thearithmetic operations performed by the first method and the secondmethod fulfill (A∘B) ●B=A, where ∘ represents a first operatorrepresenting the arithmetic operation to be performed by the firstmethod, the ● represents a second operator representing the arithmeticoperation to be performed by the second method, and A and B eachrepresent an arbitrary value.

In one embodiment of the invention, the information re-encodingapparatus further includes a first storage section for storing theplurality of pieces of second scrambled information and the plurality ofsecond parities in order to supply the plurality of pieces of secondscrambled information with the plurality of second parities.

In one embodiment of the invention, the information re-encodingapparatus further includes a second storage section for storing theplurality of third scrambling patterns and the plurality of thirdparities.

In one embodiment of the invention, the plurality of pieces of firstencoded information include a plurality of first parities. The encodedinformation generation section includes a third parity generationsection for generating a plurality of third parities in correspondencewith the plurality of third scrambling patterns; and a second paritygeneration section for performing an arithmetic operation on theplurality of third parities with respect to the plurality of firstparities by the first method, so as to generate the plurality of secondparities.

In one embodiment of the invention, the third parity generation sectionis a division circuit.

In one embodiment of the invention, the third parity generation sectiongenerates the plurality of third parities by erasure correction.

In one embodiment of the invention, the plurality of pieces of firstscrambled information are N pieces of information, the plurality ofthird scrambling patterns are M pieces of information (N>M≧1; M and Nare each an integer; and M is a divisor of N), the plurality of firstparities are N pieces of information, and the plurality of thirdparities are M pieces of information. The scrambled informationgeneration section performs an arithmetic operation on one correspondingthird scrambling pattern among the plurality of third scramblingpatterns with respect to each of the plurality of pieces of firstscrambled information by the first method, such that the plurality ofthird scrambling patterns are repeated N/M times, so as to generate Npieces of second scrambled information. The second parity generationsection performs an arithmetic operation on one corresponding thirdparity among the plurality of third parities with respect to each of theplurality of first parities by the first method, such that the pluralityof third parities are repeated N/M times, so as to generate N pieces ofsecond parities.

In one embodiment of the invention, N is 32 and M is 2.

According to still another aspect of the invention, an informationre-encoding method for re-encoding a plurality of pieces of firstencoded information into a plurality of pieces of second encodedinformation is provided. The plurality of pieces of first encodedinformation include a plurality of first scrambled information scrambledby performing an arithmetic operation on a plurality of first scramblingpatterns with respect to a plurality of pieces of information by a firstmethod. The plurality of pieces of second encoded information include aplurality of pieces of second scrambled information scrambled byperforming an arithmetic operation on a plurality of second scramblingpatterns with respect to the plurality of pieces of information by thefirst method, and a plurality of second parities. The informationre-encoding method includes the steps of (a) performing an arithmeticoperation on the plurality of first scrambling patterns with respect tothe plurality of second scrambling patterns by a second method, therebygenerating a plurality of third scrambling patterns; (b) performing anarithmetic operation on the plurality of third scrambling patterns withrespect to the plurality of pieces of first scrambled information by thefirst method, thereby generating the plurality of pieces of secondscrambled information; and (c) supplying the plurality of pieces ofsecond scrambled information with the plurality of second parities,thereby generating the plurality of pieces of second encodedinformation. The arithmetic operations performed by the first method andthe second method fulfill (A∘B) ●B=A, where ∘ represents a firstoperator representing the arithmetic operation to be performed by thefirst method, the ● represents a second operator representing thearithmetic operation to be performed by the second method, and A and Beach represent an arbitrary value.

In one embodiment of the invention, the information re-encoding methodfurther includes the step of storing the plurality of pieces of secondscrambled information and the plurality of second parities in order tosupply the plurality of pieces of second scrambled information with theplurality of second parities.

In one embodiment of the invention, the information re-encoding methodfurther includes the step of storing the plurality of third scramblingpatterns and the plurality of third parities.

In one embodiment of the invention, the plurality of pieces of firstencoded information include a plurality of first parities. Step (c)includes the steps of (c-1) generating a plurality of third parities incorrespondence with the plurality of third scrambling patterns; and(c-2) performing an arithmetic operation on the plurality of thirdparities with respect to the plurality of first parities by the firstmethod, thereby generating the plurality of second parities.

In one embodiment of the invention, step (c-1) includes the step ofgenerating the plurality of third parities by division operation.

In one embodiment of the invention, step (c-1) includes the step ofgenerating the plurality of third parities by erasure correction.

In one embodiment of the invention, the plurality of pieces of firstscrambled information are N pieces of information, the plurality ofthird scrambling patterns are M pieces of information (N>M≧1; M and Nare each an integer; and M is a divisor of N), the plurality of firstparities are N pieces of information, and the plurality of thirdparities are M pieces of information. Step (b) includes the step ofperforming an arithmetic operation on one corresponding third scramblingpattern among the plurality of third scrambling patterns with respect toeach of the plurality of pieces of first scrambled information by thefirst method, such that the plurality of third scrambling patterns arerepeated N/M times, thereby generating N pieces of second scrambledinformation; and step (c-2) includes the step of performing anarithmetic operation on one corresponding third parity among theplurality of third parities with respect to each of the plurality offirst parities by the first method, such that the plurality of thirdparities are repeated N/M times, thereby generating N pieces of secondparities.

In one embodiment of the invention, N is 32 and M is 2.

Thus, the invention described herein makes possible the advantages ofproviding an information encoding apparatus and method for shorteningthe time required for generating a scrambling pattern by reducing thenumber of times that the scrambling pattern is to be generated and alsofor reducing a capacity of the storage section which is temporarilyused; and an information re-encoding apparatus and method for reducingthe time required for generating a plurality of pieces of secondinformation from a plurality of pieces of first information and also forreducing a capacity of the storage section which is temporarily used.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an error correction format used in examples of the presentinvention;

FIG. 2 shows a sector format;

FIG. 3 shows a structure of an information encoding apparatus 100according to a first example of the present invention;

FIG. 4 shows an example in which an addition section 104 adds scramblingpatterns to a plurality of pieces of information;

FIG. 5 show a structure of a pattern generation section 102;

FIG. 6 shows an example of a parity generation section 105;

FIG. 7 is a flowchart illustrating a procedure for encoding informationby the information encoding apparatus 100;

FIG. 8 shows a structure of an information encoding apparatus 700according to a second example of the present invention;

FIG. 9 is a flowchart illustrating a procedure for encoding informationby the information encoding apparatus 700;

FIG. 10 shows a structure of an information re-encoding apparatus 800according to a third example of the present invention;

FIG. 11 shows an exemplary format of information to be stored in asecond storage section 802;

FIG. 12 shows an example in which an addition section 805 addsdifferential scrambling patterns to a plurality of pieces of scrambledinformation;

FIG. 13 shows an example in which the addition section 805 addsdifferential parities corresponding to the differential scramblingpatterns to first parities corresponding to the plurality of pieces ofscrambled information;

FIG. 14 is a flowchart illustrating a procedure for re-encoding aplurality of pieces of first encoded information into a plurality ofpieces of second encoded information by the information re-encodingapparatus 800;

FIG. 15 shows a structure of an information re-encoding apparatus 1200according to a fourth example of the present invention;

FIG. 16 is a flowchart illustrating a procedure for re-encoding theplurality of pieces of first encoded information into the plurality ofpieces of second encoded information by the information re-encodingapparatus 1200;

FIG. 17 shows a conventional information encoding apparatus 1500;

FIG. 18 illustrates re-encoding of information; and

FIG. 19 shows another conventional information encoding apparatus 1700.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described by way ofillustrative examples with reference to the accompanying drawings.

The error correction code used in first through fourth examples of thepresent invention is a Read-Solomon code RS (248, 216) over an extensionfield obtained from a prime field GF (2) by adjoining a root α of theprimitive polynomial (expression 1). Here, the number of errorcorrection codes in one unit is 304.x ⁸ +x ⁴ +X ³ +x ²+1=0  Expression 1

FIG. 1 shows an error correction code format used in the first throughfourth examples of the present invention.

The number of sectors for error correction codes in one unit is 32. Userdata 0 and error detection code EDC0 are included in one sector.Similarly, user data 1 and error detection code EDC1 are included in onesector, and user data 2 and error detection code EDC2 are included inone sector, etc. User data 31 and error detection code EDC31 areincluded in one sector.

FIG. 2 shows a sector format.

One sector includes user data and an error detection code. User data is,for example, 2048-byte data for a moving picture. An error detectioncode (EDC) is for detecting an erroneous error correction at the time ofdata reproduction, and is 4-byte data. The error detection code iscalculated based on each of the coefficients of a polynomial a (x)obtained from expression 2.a(x)·x ³² mod x ³² +x ³¹ +x ⁴+1  Expression 2

EXAMPLE 1

FIG. 3 shows a structure of an information encoding apparatus 100according to the first example of the present invention.

The information encoding apparatus 100 includes a first storage section101, a pattern generation section 102, a second storage section 103, anaddition section 104, and a parity generation section 105.

The first storage section 101 stores scrambled information and a parityin order to supply the scrambled information with the parity.

The first storage section 101 includes a data area 106 and a parity area107.

In the data area 106, scrambled data (scrambled information), data to beencoded (information to be encoded), or encoded data (encodedinformation) is to be stored.

In the parity area 107, parities are to be stored.

The pattern generation section 102 generates M pieces of (M periods of)scrambling patterns. The number of scrambling patterns (number ofperiods of scrambling patterns) generated by the pattern generationsection 102 is less than the number (N) of pieces of information to beencoded (N>M≧1; where M and N are each an integer). The patterngeneration section 102 outputs M scrambling patterns to the secondstorage section 103. The pattern generation section 102 will bedescribed below in more detail.

The second storage section 103 stores scrambling patterns.

The addition section 104 applies, to each of the N pieces of informationto be encoded, one corresponding scrambling pattern among the Mscrambling patterns, so as to generate N pieces of scrambledinformation. Each of at least one of the M scrambling patterns isapplied to two or more of the N pieces of information. The N pieces ofscrambled information are stored in the data area 106.

The parity generation section 105 generates N parities in correspondencewith the N pieces of scrambled information. The generation section 105will be described below in more detail.

For example, M scrambling patterns are M sectors of scrambling patterns.N pieces of information are N sectors of information.

FIG. 4 shows an example in which the addition section 104 addsscrambling patterns to a plurality of pieces of information.

The addition section 104 adds one sector of scrambling patterns storedin the second storage section 103 and the first sector information among32 sectors of data stored in the data area 106, so as to generate onesector of scrambled information. The addition section 104 adds onesector of scrambling patterns stored in the second storage section 103and the second sector information among 32 sectors of data stored in thedata area 106, so as to generate one sector of scrambled information.

Thus, the addition section 104 sequentially adds one sector ofscrambling patterns stored in the second storage section 103 and eachsector information among 32 sectors of data stored in the data area 106,so as to generate 32 sectors of scrambled information. The generated 32sectors of scrambled information are stored in the data area 106.

FIG. 5 shows a structure of the pattern generation section 102.

The pattern generation section 102 includes 16 memory devices 401through 416 and three adders 417 through 419.

For generating a scrambling pattern, the species of scrambling isdetermined in accordance with the position on the recording medium atwhich the information is to be recorded. For example, specific 16 bits(s15 through s0) of the physical block number are used. By outputtingthe values of s7 through s0 each time the shift registers are shifted 8times, 2052-byte scrambling patterns are generated. In a specificexample, the stream of the scrambling patterns which is generated whenthe species of scrambling is C000h (s15 and s14 are 1 and other bits are0) is 00h, 44h, 46h, 86h, 96h, . . . 38h, 12h, A2h.

FIG. 6 shows an example of the parity generation section 105. The paritygeneration section 105 shown in FIG. 6 is formed of a division circuit.

The parity generation section 105 includes 32 8-bit memory devices 601through 632, 32 8-bit adders 633 through 664, and 32 coefficientmultipliers 665 through 696. The value of the 8-bit memory devices 601through 632 is initially 00h (cleared state). 216-byte data forming aninformation section of the code word is sequentially input to the 8-bitmemory devices 601 through 632 as code word data. The data stored in the8-bit memory devices 601 through 632, after the 216-byte data is inputto the 8-bit memory devices 601 through 632, is the parity to becalculated. By performing this processing for all 304 code words, 32sectors of scrambled information are error correction encoded.

FIG. 7 shows a procedure for encoding information by the informationencoding apparatus 100.

Hereinafter, the procedure will be described step by step.

It is assumed here that the data area 106 has 32 sectors of informationto be encoded stored therein.

Step 1301: The pattern generation section 102 generates one sector (oneperiod) of scrambling patterns. For example, the pattern generationsection 102 sets the species of scrambling for generating scramblingpatterns at s15 through s0. The pattern generation section 102 outputsthe value of s7 through s0 each time the shift registers are shifted 8times, so as to generate one sector of scrambling patterns (2052 bytes).

After this, the processing advances to step 1302.

Step 1302: The pattern generation section 102 outputs one sector ofscrambling patterns to the second storage section 103.

After this, the processing advances to step 1303.

Step 1303: The second storage section 103 stores the one sector ofscrambling patterns. The addition section 104 adds the one sector ofscrambling patterns stored in the second storage section 103 and thefirst sector information among 32 sectors of data stored in the dataarea 106, so as to generate one sector of scrambled information. Theaddition section 104 adds one sector of scrambling patterns stored inthe second storage section 103 and the second sector information among32 sectors of data stored in the data area 106, so as to generate onesector of scrambled information. Thus, the addition section 104sequentially adds one sector of scrambling patterns stored in the secondstorage section 103 and each sector information among 32 sectors of datastored in the data area 106, so as to generate 32 sectors of scrambledinformation. The generated 32 sectors of scrambled information arestored in the data area 106.

After this, the processing advances to step 1304.

Step 1304: The parity generation section 105 generates 32 sectors ofparities in correspondence with the 32 sectors of scrambled informationstored in the data area 106.

After this, the processing advances to step 1305.

Step 1305: The parity generation section 105 outputs the generated 32sectors of parities to the parity area 107. Thus, 32 sectors ofscrambled information are supplied with 32 sectors of parities, so thatencoded information is generated.

Then, the processing is completed.

According to the information encoding apparatus and method of thepresent invention, one corresponding scrambling pattern among Mscrambling patterns is applied to each of N pieces of information(N>M≧1; where M and N are each an integer), so that N pieces ofscrambled information are generated. Each of at least one of Mscrambling patterns is applied to two or more of the N pieces ofinformation.

Therefore, it is sufficient to generate M scrambling patterns for Npieces of information. It is not necessary to generate N scramblingpatterns.

As a result, the number of times that the scrambling patterns need to begenerated can be reduced, and thus the time required for generatingscrambling patterns can be shortened.

In the first example, error correction codes having an error correctionunit of 32 sectors and a sector size of 2052 bytes are used. The patterngeneration section 102 generates one sector of scrambling patterns. Thetype of code used and the number of scrambling patterns generated by thepattern generation section 102 are not limited to the above. The type ofcode and the number of scrambling patterns generated by the patterngeneration section 102 are arbitrary, as long as N pieces of scrambledinformation are generated by applying to, the N pieces of information,one corresponding scrambling pattern among the M scrambling patterns(N>M≧1; where M and N are each an integer) and each of at least one ofthe M scrambling patterns is applied to two or more of the N pieces ofinformation.

For example, when M is a divisor of N, the addition section 104 appliesone corresponding scrambling pattern among the M scrambling patterns toeach of the N pieces of information such that the M scrambling patternsare repeated N/M times, so as to generate N pieces of scrambledinformation.

One storage section may be divided into a plurality of areas, in whichcase one of the plurality of areas is used as the first storage section101 and another one of the plurality of areas is used as the secondstorage section 103.

In the case where the information encoding apparatus 100 is included inthe recording and reproduction apparatus, a section for performing errorcorrection while reproduction may be used as the parity generationsection 105 and parities may be generated by performing erasurecorrection.

In the first example, in order to generate N pieces of scrambledinformation, the addition section 104 adds each of the N pieces ofinformation and one corresponding scrambling pattern among M scramblingpatterns. The form of application is not limited to addition, as long asone corresponding scrambling pattern among M scrambling patterns isapplied to each of the N pieces of information for generating N piecesof scrambled information. The form of application may be subtraction. Inthis case, the information encoding apparatus 100 includes a subtractionsection instead of, or in addition to, the addition section 104.

In the example shown in FIG. 3, the pattern generation section 102 actsas the “scrambling pattern generation section for generating Mscrambling patterns (N >M≧1; where M and N are each an integer)”. Thefirst storage section 101, the second storage section 103, and theaddition section 104 together acts as the “scrambled informationgeneration section for applying, to each of the N pieces of information,one corresponding scrambling pattern among the M scrambling patterns soas to generate N pieces of scrambled information”. The first storagesection 101 and the parity generation section 105 together act as the“encoded information generation section for supplying the N pieces ofscrambled information with N parities, respectively, so as to generateencoded information”. However, the elements included in the informationencoding apparatus according to the present invention are not limited tothe above.

The information encoding apparatus according to the present inventionmay have any structure as long as including elements acting as the“scrambling pattern generation section for generating M scramblingpatterns (N>M≧1; where M and N are each an integer)”, the “scrambledinformation generation section for applying, to each of the N pieces ofinformation, one corresponding scrambling pattern among the M scramblingpatterns so as to generate N pieces of scrambled information”, and the“encoded information generation section for supplying the N pieces ofscrambled information with N parities, respectively, so as to generateencoded information”.

EXAMPLE 2

FIG. 8 shows a structure of an information encoding apparatus 700according to the second example of the present invention.

The information encoding apparatus 700 includes a storage section 101, apattern generation section 702, an addition section 703, and a paritygeneration section 105.

The storage section 101 includes the data area 106 and the parity area107.

In FIG. 8, identical elements to those described with reference to FIG.3 bear identical reference numerals thereto and detailed descriptionsthereof will be omitted.

The pattern generation section 702 is substantially the same as thepattern generation section 102 of the information encoding apparatus 100except for outputting M scrambling patterns to the addition section 703,and thus will not be described in detail.

The addition section 703 applies, to each of the N pieces of informationto be encoded, one corresponding scrambling pattern among the Mscrambling patterns, so as to generate N pieces of scrambledinformation. Each of at least one of the M scrambling patterns isapplied to two or more of the N pieces of information. The N pieces ofscrambled information are stored in the data area 106. For example, theaddition section 703 generates 32 sectors of scrambled information.

The addition section 703 adds a value represented by the ith byte of onesector of scrambling patterns (i bytes; i=1, 2, . . . , 2052) and avalue represented by the ith byte of each sector of 32 sectors ofinformation. Thus, the addition section 703 sequentially adds one sectorof scrambling patterns output from the pattern generation section 702and each of 32 sectors of information stored in the data area 106.

FIG. 9 shows a procedure for encoding information by the informationencoding apparatus 700.

Hereinafter, the procedure will be described step by step. In FIG. 9,identical steps to those described with reference to FIG. 7 bearidentical reference numerals thereto and detailed descriptions thereofwill be omitted.

Step 1802: The pattern generation section 702 sequentially outputs onesector of scrambling patterns to the addition section 703.

After this, the processing advances to step 1803.

Step 1803: The addition section 703 generates 32 sectors of scrambledinformation. The generated 32 sectors of scrambled information arestored in the data area 106. The addition section 703 adds a valuerepresented by the ith byte of one sector of scrambling patterns (ibytes; i =1, 2, . . . , 2052) and a value represented by the ith byte ofeach sector of 32 sectors of information. Thus, the addition section 703sequentially adds one sector of scrambling patterns output from thepattern generation section 702 and each of 32 sectors of informationstored in the data area 106.

According to the information encoding apparatus and method of thepresent invention, one corresponding scrambling pattern among Mscrambling patterns is applied to each of N pieces of information(N>M≧1; where M and N are each an integer), so that N pieces ofscrambled information are generated. Each of at least one of Mscrambling patterns is applied to two or more of the N pieces ofinformation.

Therefore, it is sufficient to generate M scrambling patterns for Npieces of information. It is not necessary to generate N scramblingpatterns.

As a result, the number of times that the scrambling patterns need to begenerated can be reduced, and thus the time required for generatingscrambling patterns can be shortened.

In the second example, error correction codes having an error correctionunit of 32 sectors and a sector size of 2052 bytes are used. The patterngeneration section 702 generates one sector of scrambling patterns. Thetype of code used and the number of scrambling patterns generated by thepattern generation section 702 are not limited to the above. The type ofcode and the number of scrambling patterns generated by the patterngeneration section 702 are arbitrary, as long as N pieces of scrambledinformation are generated by applying to, each of the N pieces ofinformation, one corresponding scrambling pattern among the M scramblingpatterns (N>M≧1; where M and N are each an integer) and each of at leastone of the M scrambling patterns is applied to two or more of the Npieces of information.

For example, when M is a divisor of N, the addition section 703 appliesone corresponding scrambling pattern among the M scrambling patterns toeach of the N pieces of information such that the M scrambling patternsare repeated N/M times, so as to generate N pieces of scrambledinformation.

In the case where the information encoding apparatus 700 is included inthe recording and reproduction apparatus, a section for performing errorcorrection while reproduction may be used as the parity generationsection 105 and parities may be generated by performing erasurecorrection.

In the second example, in order to generate N pieces of scrambledinformation, the addition section 703 adds each of the N pieces ofinformation and one corresponding scrambling pattern among M scramblingpatterns. The form of application is not limited to addition, as long asone corresponding scrambling pattern among M scrambling patterns isapplied to each of the N pieces of information for generating N piecesof scrambled information. The form of application may be subtraction. Inthis case, the information encoding apparatus 700 includes a subtractionsection instead of, or in addition to, the addition section 703.

In the example shown in FIG. 8, the pattern generation section 702 actsas the “scrambling pattern generation section for generating Mscrambling patterns (N >M≧1; where M and N are each an integer)”. Thefirst storage section 101 and the addition section 703 together acts asthe “scrambled information generation section for applying, to each ofthe N pieces of information, one corresponding scrambling pattern amongthe M scrambling patterns so as to generate N pieces of scrambledinformation”. The first storage section 101 and the parity generationsection 105 together act as the “encoded information generation sectionfor supplying the N pieces of scrambled information with N parities,respectively, so as to generate encoded information”. However, theelements included in the information encoding apparatus according to thepresent invention are not limited to the above.

The information encoding apparatus according to the present inventionmay have any structure as long as including elements acting as the“scrambling pattern generation section for generating M scramblingpatterns (N>M≧1; where M and N are each an integer)”, the “scrambledinformation generation section for applying, to each of the N pieces ofinformation, one corresponding scrambling pattern among the M scramblingpatterns so as to generate N pieces of scrambled information”, and the“encoded information generation section for supplying the N pieces ofscrambled information with N parities, respectively, so as to generateencoded information”.

EXAMPLE 3

FIG. 10 shows a structure of an information re-encoding apparatus 800according to the third example of the present invention.

The information re-encoding apparatus 800 includes a first storagesection 801, a second storage section 802, a pattern generation section803, a parity generation section 804, and an addition section 805.

The information re-encoding apparatus 800 re-encodes a plurality ofpieces of first encoded information into a plurality of pieces of secondencoded information. The plurality of pieces of first encodedinformation include a plurality of pieces of first scrambled informationscrambled by performing an arithmetic operation on a plurality of firstscrambling patterns with respect to a plurality of pieces of informationby a first method, and a plurality of first parities. The plurality ofpieces of second encoded information include a plurality of pieces ofsecond scrambled information scrambled by performing an arithmeticoperation on a plurality of second scrambling patterns with respect tothe plurality of pieces of information by the first method, and aplurality of second parities. The expression “performing an arithmeticoperation on a plurality of first scrambling patterns with respect to aplurality of pieces of information by a first method” means, forexample, adding the plurality of information and the plurality of firstscrambling patterns.

The first storage section 801 stores scrambled information and paritiesfor supplying the scrambled information with the parities.

The first storage section 801 includes a data area 806 and a firstparity area 807.

In the data area 806, scrambled data (scrambled information), data to beencoded (information to be encoded), or encoded data (encodedinformation) is to be stored.

In the first parity area 807, parities are to be stored.

The second storage section 802 stores scrambling patterns and paritiesfor supplying the scrambling patterns with the parities.

The second storage section 802 includes a pattern area 808 and a secondparity area 809.

In the pattern area 808, scrambling patterns are to be stored.

In the second parity area 809, parities are to be stored.

The pattern generation section 803 is substantially the same as thepattern generation section 102 of the information encoding apparatus 100except for generating a plurality of third scrambling patterns byperforming an arithmetic operation on the plurality of first scramblingpatterns with respect to the plurality of second scrambling patterns bya second method, and thus will not be described in detail. Theexpression “performing an arithmetic operation on the plurality of firstscrambling patterns with respect to the plurality of second scramblingpatterns by a second method” means, for example, obtaining a differencebetween the plurality of second scrambling patterns and the plurality offirst scrambling patterns. In this case, the pattern generation section803 obtains the difference between the plurality of second scramblingpatterns and the plurality of first scrambling patterns, so as togenerate a plurality of differential scrambling patterns.

The addition section 805 performs an arithmetic operation on theplurality of third scrambling patterns stored in the pattern area 808with respect to the plurality of first scrambling patterns stored in thedata area 806 by the first method, so as to generate a plurality ofpieces of second scrambled information.

When M is a divisor of N, the addition section 805, for example,performs an arithmetic operation on one corresponding scrambling patternamong M third scrambling patterns with respect to each of N pieces (Nsectors) of first scrambled information by the first method, such thatthe M (M sectors of) scrambling patterns are repeated N/M times, so asto generate N pieces of second scrambled information. The additionsection 805, for example, further performs an arithmetic operation onone corresponding parity among M third parities with respect to each ofN first parities stored in the first parity area 807 by the firstmethod, such that the M third parities stored in the second parity area809 are repeated N/M times, so as to generate N second parities.

The parity generation section 804 is substantially the same as theparity generation section 105 in the information encoding apparatus 100except for generating the plurality of third parities in correspondencewith the plurality of third scrambling patterns stored in the patternarea 808, and thus will not be described in detail.

In the third example, the expression “performing an arithmetic operationon information B with respect to information A by a first method” meansadding information A and information B (A+B). The expression “performingan arithmetic operation on information B with respect to information Aby a second method ” means obtaining a difference between information Aand information B (A−B, or B−A). As long as the arithmetic operationperformed by the first method and the arithmetic operation performed bythe second method fulfill (A∘B) ●B=A, the arithmetic operation performedby the first method is not limited to addition and the arithmeticoperation performed by the second method is not limited to obtaining adifference. In the case where an arithmetic operation is performed oninformation B with respect to information A by the first method, theinformation re-encoding apparatus 800 includes a first arithmeticoperation section for performing a first arithmetic operation oninformation A and information B instead of, or in addition to, theaddition section 805. In the case where an arithmetic operation isperformed on information B with respect to information A by the secondmethod, the information re-encoding apparatus 800 includes a secondarithmetic operation section for performing a second arithmeticoperation on information A and information B instead of, or in additionto, the addition section 805.

The symbol “∘” represents a first operator representing the arithmeticoperation to be performed by the first method, and the symbol “●”represents a second operator representing the arithmetic operation to beperformed by the second method. Information A and information Brepresent an arbitrary value.

FIG. 11 shows an exemplary format of the information stored in thesecond storage section 802.

Pattern data 0 and pattern data 1 are each one sector (2052-byte) ofscrambling patterns.

FIG. 12 shows an example in which the addition section 805 addsdifferential scrambling patterns to a plurality of pieces of scrambledinformation.

The addition section 805 adds pattern data 0 stored in the pattern area808 to each pair of user data 0 and error detection code EDC0, user data2 and error detection code EDC2, user data 4 and error detection codeEDC4, . . . user data 30 and error detection code EDC30 stored in thedata area 806. Similarly, the addition section 805 adds pattern data 1stored in the pattern area 808 to each pair of user data 1 and errordetection code EDC1, user data 3 and error detection code EDC3, userdata 5 and error detection code EDC5, . . . user data 31 and errordetection code EDC31 stored in the data area 806.

Thus, the addition section 805 adds each of N sectors of first scrambledinformation and one corresponding differential scrambling pattern amongM sectors of differential scrambling patterns, such that the M sectorsof differential scrambling patterns are repeated N/M times, so as togenerate N sectors of second scrambled information. M is a divisor of N,and a differential scrambling pattern is a scrambling pattern generatedby obtaining a difference between the first scrambling pattern and thesecond scrambling pattern. The first scrambled information isinformation scrambled with the first scrambling pattern, and the secondscrambled information is information scrambled with the secondscrambling pattern.

FIG. 13 shows an example in which the addition section 805 addsdifferential parities corresponding to the differential scramblingpatterns and the first parities corresponding to a plurality of piecesof scrambled information.

The addition section 805 adds two sectors of differential paritiesstored in the second parity area 809 to the first two sectors (the firstsector and the second sector) of first parities among 32 sectors offirst parities stored in the first parity area 807, so as to generatetwo sectors of second parities. The addition section 805 also adds twosectors of differential parities stored in the second parity area 809 tothe next two sectors (the third sector and the fourth sector) of firstparities among 32 sectors of first parities stored in the first parityarea 807, so as to generate two sectors of second parities.

Thus, the addition section 805 adds each of the N sectors of firstparities and one corresponding differential parity among M sectors ofdifferential parities, such that the M sectors of differential paritiesare repeated N/M times, so as to generate N sectors of second parities.M is a divisor of N, and a differential parity is a parity generated byobtaining a difference between the first parity and the second parity.The first parity is a parity corresponding to the first scrambledinformation, and the second parity is a parity corresponding to thesecond scrambled information. The first scrambled information isinformation scrambled with the first scrambling pattern, and the secondscrambled information is information scrambled with the secondscrambling pattern.

FIG. 14 shows a procedure for re-encoding a plurality of pieces of firstencoded information into a plurality of pieces of second encodedinformation by the information re-encoding apparatus 800.

Hereinafter, the procedure will be described step by step.

The plurality of pieces of first encoded information include a pluralityof pieces of first scrambled information scrambled by performing anarithmetic operation on the plurality of first scrambling patterns withrespect to a plurality of pieces of information by a first method(addition), and a plurality of first parities. The plurality of piecesof second encoded information include a plurality of pieces of secondscrambled information scrambled by performing an arithmetic operation onthe plurality of second scrambling patterns with respect to theplurality of pieces of information by the first method (addition), and aplurality of second parities.

It is assumed here that the first storage section 801 has 32 sectors offirst encoded information stored therein, and that the data area 806 has32 sectors of first scrambled information stored therein. It is alsoassumed that the first parity area 807 has 32 sectors of first paritiesstored therein.

Step 1401: The pattern generation section 803 generates two sectors (twoperiods) of differential scrambling patterns. Differential scramblingpatterns are generated by obtaining a difference between the firstscrambling patterns and the second scrambling patterns. For example,where the species of scrambling for generating the first scramblingpatterns is SB and the species of scrambling for generating the secondscrambling patterns is SC, the pattern generation section 803 sets thespecies of scrambling for generating the differential scramblingpatterns (difference between SB and SC; SC−SB) at s15 through s0. In theerror correction code format used in the third example, two sectors ofdifferential scrambling patterns are generated from LCM (2052,216)/2052=2. The two sectors of scrambling patterns corresponds to 4104bytes as a result of one sector of scrambling patterns (2052 bytes)being repeated twice.

After the two sectors of scrambling patterns (4104 bytes) are generated,the processing advances to step 1402.

Step 1402: The pattern generation section 803 outputs two sectors ofdifferential scrambling patterns to the pattern area 808.

After this, the processing advances to step 1403.

Step 1403: The pattern area 808 stores the two sectors of differentialscrambling patterns. The parity generation section 804 generates twosectors of differential parities in correspondence with the two sectorsof differential scrambling patterns. In the error correction code formatused in the third example, 19 code words of differential parities aregenerated.

After this, the processing advances to step 1404.

Step 1404: The parity generation section 804 outputs the two sectors ofdifferential parities to the second parity area 809.

After this, the processing advances to step 1405.

Step 1405: The second parity area 809 stores the two sectors ofdifferential parities. The addition section 805 adds each of the 32sectors of first scrambled information stored in the data area 806 andone corresponding differential scrambling pattern among the two sectorsof differential scrambling patterns, such that the two sectors ofdifferential scrambling patterns are repeated 16 times, so as togenerate 32 sectors of second scrambled information. For example, theaddition section 805 adds pattern data 0 stored in the pattern area 808to each pair of user data 0 and error detection code EDC0, user data 2and error detection code EDC2, user data 4 and error detection codeEDC4, . . . user data 30 and error detection code EDC30 stored in thedata area 806. Similarly, the addition section 805 adds pattern data 1stored in the pattern area 808 to each pair of user data 1 and errordetection code EDC1, user data 3 and error detection code EDC3, userdata 5 and error detection code EDC5, . . . user data 31 and errordetection code EDC31 stored in the data area 806 (see FIG. 12).

After the 32 sectors of second scrambled information are generated, theprocessing advances to step 1406.

Step 1406: The addition section 805 outputs the 32 sectors of secondscrambled information to the data area 806.

After this, the processing advances to step 1407.

Step 1407: The data area 806 stores the 32 sectors of second scrambledinformation. The addition section 805 adds two sectors of differentialparities stored in the second parity area 809 to the first two sectors(the first sector and the second sector) of first parities among 32sectors (304 code words) of first parities stored in the first parityarea 807, so as to generate two sectors of second parities. The additionsection 805 also adds two sectors of differential parities stored in thesecond parity area 809 to the next two sectors (the third sector and thefourth sector) of first parities among 32 sectors of first paritiesstored in the first parity area 807, so as to generate two sectors ofsecond parities.

Thus, the addition section 805 adds each of the 32 sectors of firstparities and one corresponding differential parity among two sectors ofdifferential parities, such that the two sectors of differentialparities are repeated 16 times, so as to generate 32 sectors of secondparities.

After the 32 sectors of second parities are generated, the processingadvances to step 1408.

Step 1408: The addition section 805 outputs the 32 sectors of secondparities to the first parity area 807. The 32 sectors of secondscrambled information are supplied with 32 sectors of second parities,so that 32 sectors of second encoded information are generated.

After this, the processing is completed.

According to the information re-encoding apparatus and method of thepresent invention, a plurality of third scrambling patterns aregenerated by performing an arithmetic operation on a plurality of firstscrambling patterns with respect to a plurality of second scramblingpatterns by a second method, and a plurality of pieces of secondscrambled information are generated by performing an arithmeticoperation on the plurality of third scrambling patterns with respect toa plurality of pieces of first scrambled information by a first method.The arithmetic operations performed by the first method and the secondmethod fulfill (A∘B) ●B=A. The symbol “∘” represents a first operatorrepresenting the arithmetic operation to be performed by the firstmethod, and the symbol “●” represents a second operator representing thearithmetic operation to be performed by the second method. Information Aand information B represent an arbitrary value.

By re-scrambling the plurality of pieces of first scrambled information,a plurality of pieces of second scrambled information can be generatedfrom the plurality of pieces of first scrambled information withoutgenerating a plurality of pieces of information. Thus, the time requiredfor generating the plurality of pieces of second encoded informationfrom the plurality of pieces of first encoded information can beshortened.

In the third example, the expression “performing an arithmetic operationon information B with respect to information A by a first method” meansadding information A and information B (A+B). The expression “performingan arithmetic operation on information B with respect to information Aby a second method ” means obtaining a difference between information Aand information B (A−B, or B−A). As long as the arithmetic operationperformed by the first method and the arithmetic operation performed bythe second method fulfill (A∘B) ●B=A, the arithmetic operation performedby the first method is not limited to addition and the arithmeticoperation performed by the second method is not limited to obtaining adifference.

In the third example, error correction codes having an error correctionunit of 32 sectors, a sector size of 2052 bytes, and an informationsection of the code word of 216 bytes are used. The pattern generationsection 803 generates two sectors of differential scrambling patterns.The type of code used and the number of scrambling patterns generated bythe pattern generation section 803 are not limited to the above. Thetype of code and the number of scrambling patterns generated by thepattern generation section 803 are arbitrary, as long as a plurality ofthird scrambling patterns are generated by performing an arithmeticoperation on a plurality of first scrambling patterns with respect to aplurality of second scrambling patterns by a second method, and aplurality of pieces of second scrambled information are generated byperforming an arithmetic operation on the plurality of third scramblingpatterns with respect to a plurality of pieces of first scrambledinformation by a first method. The arithmetic operations performed bythe first method and the second method fulfill (A∘B) ●B=A. The symbol“∘” represents a first operator representing the arithmetic operation tobe performed by the first method, and the symbol “●” represents a secondoperator representing the arithmetic operation to be performed by thesecond method. Information A and information B represent an arbitraryvalue.

For example, when the arithmetic operation performed by the secondmethod is obtaining a difference, differential scrambling patterns aregenerated as the third scrambling patterns. The size of the thirdscrambling patterns may be determined by LCM (sector size, size of theinformation section of the code word)/sector size.

In the third example, a Read-Solomon code is used as the errorcorrection code. The error correction code is not limited to theRead-Solomon code as long as the error correction code is linear.

One storage section may be divided into a plurality of areas, in whichcase one of the plurality of areas is used as the first storage section801 and another one of the plurality of areas is used as the secondstorage section 802.

In the case where the information re-encoding apparatus 800 is includedin the recording and reproduction apparatus, a section for performingerror correction while reproduction may be used as the parity generationsection 804 and parities may be generated by performing erasurecorrection.

In the example shown in FIG. 10, the second storage section 802 and thepattern generation section 803 together act as the “third scramblingpattern generation section for performing an arithmetic operation on theplurality of first scrambling patterns with respect to the plurality ofsecond scrambling patterns by a second method, so as to generate aplurality of third scrambling patterns”. The first storage section 801,the second storage section 802, and the addition section 805 togetheract as the “scrambled information generation section for performing anarithmetic operation on the plurality of third scrambling patterns withrespect to the plurality of pieces of first scrambled information by thefirst method, so as to generate the plurality of pieces of secondscrambled information”. The first storage section 801, the secondstorage section 802, the parity generation section 804, and the additionsection 805 together act as the “encoded information generation sectionfor supplying the plurality of pieces of second scrambled informationwith the plurality of second parities, so as to generate the pluralityof pieces of second encoded information”. However, the elements includedin the information encoding apparatus according to the present inventionare not limited to the above.

The information re-encoding apparatus according to the present inventionmay have any structure as long as including elements acting as the“third scrambling pattern generation section for performing anarithmetic operation on the plurality of first scrambling patterns withrespect to the plurality of second scrambling patterns by a secondmethod, so as to generate a plurality of third scrambling patterns”, the“scrambled information generation section for performing an arithmeticoperation on the plurality of third scrambling patterns with respect tothe plurality of pieces of first scrambled information by the firstmethod, so as to generate the plurality of pieces of second scrambledinformation”, and the “encoded information generation section forsupplying the plurality of pieces of second scrambled information withthe plurality of second parities, so as to generate the plurality ofpieces of second encoded information”.

EXAMPLE 4

FIG. 15 shows a structure of an information re-encoding apparatus 1200according to the fourth example of the present invention.

The information re-encoding apparatus 1200 includes a storage section801, a pattern generation section 1202, an addition section 1204, and aparity generation section 1203.

The storage section 801 includes the data area 806 and the parity area807.

In FIG. 15, identical elements to those described with reference to FIG.10 bear identical reference numerals thereto and detailed descriptionsthereof will be omitted.

The pattern generation section 1202 is substantially the same as thepattern generation section 102 of the information encoding apparatus 100except for generating a plurality third scrambling patterns byperforming an arithmetic operation on a plurality of first scramblingpatterns with respect to a plurality of second scrambling patterns by asecond method and outputting the generated plurality of third scramblingpatterns to the addition section 1204 and the parity generation section1203, and thus will not be described in detail.

The parity generation section 1203 is substantially the same as theparity generation section 105 in the information encoding apparatus 100except for generating a plurality of third parities (differentialparities) in correspondence with the plurality of third scramblingpatterns (differential scrambling patterns) output from the patterngeneration section 1202, and thus will not be described in detail.

The addition section 1204 performs an arithmetic operation on theplurality of third scrambling patterns output from the patterngeneration section 1202 with respect to a plurality of pieces of firstscrambled information stored in the data area 806 by a first method(addition), so as to generate a plurality of pieces of second scrambledinformation.

When M is a divisor of N, the addition section 1204, for example,performs an arithmetic operation on one corresponding third scramblingpattern among M third scrambling patterns output from the patterngeneration section 1202 with respect to each of the N pieces (N sectors)of first scrambled information stored in the data area 806 by the firstmethod (addition), such that the M (M sectors of) third scramblingpatterns output from the pattern generation section 1202 are repeatedN/M times, so as to generate N pieces of second scrambled information.The addition section 1204 also, for example, performs an arithmeticoperation on one corresponding third parity among M third paritiesoutput from the parity generation section 1203 with respect to each ofthe N (N sectors of) first parities stored in the first parity area 807by the first method, such that the M third parities output from theparity generation section 1203 are repeated N/M times, so as to generateN second parities.

For example, the addition section 1204 sequentially adds two sectors ofdifferential scrambling patterns (i bytes; i=1 through 4104) output fromthe pattern generation section 1202 to the 32 sectors of first scrambledinformation stored in the data area 806. Namely, the addition section1204 adds the ith byte of two sectors of differential scramblingpatterns to the ith byte of the odd-numbered sectors among the 32sectors of first scrambled information for i=1 through 2052, and addsthe ith byte of two sectors of differential scrambling patterns to theith through 2052nd bytes of the even-numbered sectors among the 32sectors of first scrambled information stored in the data area 806 fori=2053 through 4104 (see FIG. 12).

The addition section 1204 adds two sectors of differential paritiesoutput from the parity generation section 1203 to the first two sectors(the first sector and the second sector) of first parities among 32sectors (304 code words) of first parities stored in the first parityarea 807, so as to generate two sectors of second parities. The additionsection 1204 also adds two sectors of differential parities output fromthe parity generation section 1203 to the next two sectors (the thirdsector and the fourth sector) of first parities among 32 sectors offirst parities stored in the first parity area 807, so as to generatetwo sectors of second parities. Thus, the addition section 1204 addseach of the 32 sectors of first parities and one correspondingdifferential parity among two sectors of differential parities, suchthat the two sectors of differential parities are repeated 16 times, soas to generate 32 sectors of second parities.

In the fourth example, the expression “performing an arithmeticoperation on information B with respect to information A by a firstmethod” means adding information A and information B (A+B). Theexpression “performing an arithmetic operation on information B withrespect to information A by a second method ” means obtaining adifference between information A and information B (A−B, or B−A). Aslong as the arithmetic operation performed by the first method and thearithmetic operation performed by the second method fulfill (A∘B) ●B=A,the arithmetic operation performed by the first method is not limited toaddition and the arithmetic operation performed by the second method isnot limited to obtaining a difference. In the case where an arithmeticoperation is performed on information B with respect to information A bythe first method, the information re-encoding apparatus 1200 includes afirst arithmetic operation section for performing a first arithmeticoperation on information A and information B instead of, or in additionto, the addition section 1204. In the case where an arithmetic operationis performed on information B with respect to information A by thesecond method, the information re-encoding apparatus 1200 includes asecond arithmetic operation section for performing a second arithmeticoperation on information A and information B instead of, or in additionto, the addition section 1204.

FIG. 16 shows a procedure for re-encoding information by the informationre-encoding apparatus 1200.

Hereinafter, the procedure will be described step by step. In FIG. 16,identical steps to those described with reference to FIG. 14 bearidentical reference numerals thereto and detailed descriptions thereofwill be omitted.

The plurality of pieces of first encoded information include a pluralityof pieces of first scrambled information scrambled by performing anarithmetic operation on the plurality of first scrambling patterns withrespect to a plurality of pieces of information by a first method(addition), and a plurality of first parities. The plurality of piecesof second encoded information include a plurality of pieces of secondscrambled information scrambled by performing an arithmetic operation onthe plurality of second scrambling patterns with respect to theplurality of pieces of information by the first method (addition), and aplurality of second parities.

It is assumed here that the first storage section 801 has 32 sectors offirst encoded information stored therein, and that the data area 806 has32 sectors of first scrambled information stored therein. It is alsoassumed that the first parity area 807 has 32 sectors of first paritiesstored therein.

Step 1902: The pattern generation section 1202 outputs two sectors ofdifferential scrambling patterns to the parity generation section 1203and the addition section 1204.

After this, the processing advances to step 1903.

Step 1903: The parity generation section 1203 generates two sectors ofdifferential parities in correspondence with the two sectors ofdifferential scrambling patterns output from the pattern generationsection 1202. In the error correction code format used in the fourthexample, 19 code words of differential parities are generated.

After this, the processing advances to step 1904.

Step 1904: The parity generation section 1203 outputs the two sectors ofdifferential parities to the addition section 1204.

After this, the processing advances to step 1905.

Step 1905: The addition section 1204 adds each of the 32 sectors offirst scrambled information stored in the data area 806 and onecorresponding differential scrambling pattern among two sectors ofdifferential scrambling patterns, such that the two sectors ofdifferential scrambling patterns output from the pattern generationsection 1202 are repeated 16 times, so as to generate 32 sectors ofsecond scrambled information. For example, the addition section 1204adds pattern data 0 output from the pattern generation section 1202 toeach pair of user data 0 and error detection code EDC0, user data 2 anderror detection code EDC2, user data 4 and error detection code EDC4, .. . user data 30 and error detection code EDC30 stored in the data area806. Similarly, the addition section 1204 adds pattern data 1 outputfrom the pattern generation section 1202 to each pair of user data 1 anderror detection code EDC1, user data 3 and error detection code EDC3,user data 5 and error detection code EDC5, . . . user data 31 and errordetection code EDC31 stored in the data area 806 (see FIG. 12).

After the 32 sectors of second scrambled information are generated, theprocessing advances to step 1906.

Step 1906: The addition section 1204 outputs the 32 sectors of secondscrambled information to the data area 806.

After this, the processing advances to step 1907.

Step 1907: The data area 806 stores the 32 sectors of second scrambledinformation. The addition section 1204 adds two sectors of differentialparities output from the parity generation section 1203 to the first twosectors (the first sector and the second sector) of first parities among32 sectors (304 code words) of first parities stored in the first parityarea 807, so as to generate two sectors of second parities. The additionsection 1204 also adds two sectors of differential parities output fromthe parity generation section 1203 to the next two sectors (the thirdsector and the fourth sector) of first parities among 32 sectors offirst parities stored in the first parity area 807, so as to generatetwo sectors of second parities.

Thus, the addition section 1204 adds each of the 32 sectors of firstparities and one corresponding differential parity among two sectors ofdifferential parities, such that the two sectors of differentialparities output from the parity generation section 1203 are repeated 16times, so as to generate 32 sectors of second parities.

After the 32 sectors of second parities are generated, the processing instep 1408 is performed, thereby generating 32 sectors of second encodedinformation. Then, the processing is completed.

According to the information re-encoding apparatus and method of thepresent invention, a plurality of third scrambling patterns aregenerated by performing an arithmetic operation on a plurality of firstscrambling patterns with respect to a plurality of second scramblingpatterns by a second method, and a plurality of pieces of secondscrambled information are generated by performing an arithmeticoperation on the plurality of third scrambling patterns with respect toa plurality of pieces of first scrambled information by a first method.The arithmetic operations performed by the first method and the secondmethod fulfill (A∘B) ●B=A. The symbol “∘” represents a first operatorrepresenting the arithmetic operation to be performed by the firstmethod, and the symbol “●” represents a second operator representing thearithmetic operation to be performed by the second method. Information Aand information B represent an arbitrary value.

By re-scrambling the plurality of pieces of first scrambled information,a plurality of pieces of second scrambled information can be generatedfrom the plurality of pieces of first scrambled information withoutgenerating a plurality of pieces of information. Thus, the time requiredfor generating the plurality of pieces of second encoded informationfrom the plurality of pieces of first encoded information can beshortened.

In the fourth example, the expression “performing an arithmeticoperation on information B with respect to information A by a firstmethod” means adding information A and information B (A+B). Theexpression “performing an arithmetic operation on information B withrespect to information A by a second method ” means obtaining adifference between information A and information B (A−B, or B−A). Aslong as the arithmetic operation performed by the first method and thearithmetic operation performed by the second method fulfill (A∘B) ●B=A,the arithmetic operation performed by the first method is not limited toaddition and the arithmetic operation performed by the second method isnot limited to obtaining a difference.

In the fourth example, error correction codes having an error correctionunit of 32 sectors, a sector size of 2052 bytes, and an informationsection of the code word of 216 bytes are used. The pattern generationsection 1202 generates two sectors of differential scrambling patterns.The type of code used and the number of scrambling patterns generated bythe pattern generation section 1202 are not limited to the above. Thetype of code and the number of scrambling patterns generated by thepattern generation section 1202 are arbitrary, as long as a plurality ofthird scrambling patterns are generated by performing an arithmeticoperation on a plurality of first scrambling patterns with respect to aplurality of second scrambling patterns by a second method, and aplurality of pieces of second scrambled information are generated byperforming an arithmetic operation on the plurality of third scramblingpatterns with respect to a plurality of pieces of first scrambledinformation by a first method. The arithmetic operations performed bythe first method and the second method fulfill (A∘B) ●B=A. The symbol“∘” represents a first operator representing the arithmetic operation tobe performed by the first method, and the symbol “●” represents a secondoperator representing the arithmetic operation to be performed by thesecond method. Information A and information B represent an arbitraryvalue.

For example, when the arithmetic operation performed by the secondmethod is obtaining a difference, differential scrambling patterns aregenerated as the third scrambling patterns. The size of the thirdscrambling patterns may be determined by LCM (sector size, size of theinformation section of the code word)/sector size.

In the fourth example, a Read-Solomon code is used as the errorcorrection code. The error correction code is not limited to theRead-Solomon code as long as the error correction code is linear.

In the case where the information encoding apparatus 1200 is included inthe recording and reproduction apparatus, a section for performing errorcorrection while reproduction may be used as the parity generationsection 1203 and parities may be generated by performing erasurecorrection.

In the example shown in FIG. 15, the pattern generation section 1202acts as the “third scrambling pattern generation section for performingan arithmetic operation on the plurality of first scrambling patternswith respect to the plurality of second scrambling patterns by a secondmethod, so as to generate a plurality of third scrambling patterns”. Thefirst storage section 801 and the addition section 1204 together act asthe “scrambled information generation section for performing anarithmetic operation on the plurality of third scrambling patterns withrespect to the plurality of pieces of first scrambled information by thefirst method, so as to generate the plurality of pieces of secondscrambled information”. The first storage section 801, the paritygeneration section 1203, and the addition section 1204 together act asthe “encoded information generation section for supplying the pluralityof pieces of second scrambled information with the plurality of secondparities, so as to generate the plurality of pieces of second encodedinformation”. However,the elements included in the information encodingapparatus according to the present invention are not limited to theabove.

The information re-encoding apparatus according to the present inventionmay have any structure as long as including elements acting as the“third scrambling pattern generation section for performing anarithmetic operation on the plurality of first scrambling patterns withrespect to the plurality of second scrambling patterns by a secondmethod, so as to generate a plurality of third scrambling patterns”, the“scrambled information generation section for performing an arithmeticoperation on the plurality of third scrambling patterns with respect tothe plurality of pieces of first scrambled information by the firstmethod, so as to generate the plurality of pieces of second scrambledinformation”, and the “encoded information generation section forsupplying the plurality of pieces of second scrambled information withthe plurality of second parities, so as to generate the plurality ofpieces of second encoded information”.

According to an information encoding apparatus of the present invention,to each of N pieces of information, one corresponding scrambling patternamong M scrambling patterns (N>M≧1; where M and N are each an integer)is applied. Thus, N pieces of scrambled information are generated. Eachof at least one of the M scrambling patterns is applied to two or moreof the N pieces of information.

Accordingly, it is sufficient to generate M scrambling patterns for Npieces of information. It is not necessary to generate N scramblingpatterns.

As a result, the number of times that the scrambling patterns need to begenerated can be reduced, and thus the time required for generatingscrambling patterns can be shortened.

According to an information re-encoding apparatus of the presentinvention, an arithmetic operation is performed on a plurality of firstscrambling patterns with respect to a plurality of second scramblingpatterns by a second method. Thus, a plurality of third scramblingpatterns are generated. An arithmetic operation is performed on aplurality of third scrambling patterns with respect to a plurality offirst scrambling patterns by a first method. Thus, a plurality of piecesof second scrambled information are generated. The arithmetic operationsperformed by the first method and the second method fulfill (A∘B) ●B=A.The symbol “∘” represents a first operator representing the arithmeticoperation to be performed by the first method, and the symbol “●”represents a second operator representing the arithmetic operation to beperformed by the second method. Information A and information Brepresent an arbitrary value.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

1. An information encoding apparatus for encoding N pieces ofinformation, the information encoding apparatus comprising: a scramblingpattern generation section for generating M scrambling patterns (N>M≧1;where M and N are each an integer); a scrambled information generationsection for applying, to each of the N pieces of information, onecorresponding scrambling pattern among the M scrambling patterns so asto generate N pieces of scrambled information; and an encodedinformation generation section for supplying the N pieces of scrambledinformation with N parities, respectively, so as to generate encodedinformation; wherein each of at least one of the M scrambling patternsis applied to two or more of the N pieces of information.
 2. Aninformation encoding apparatus according to claim 1, wherein the M is adivisor of N, and the scrambled information generation section appliesone corresponding scrambling pattern among the M scrambling patterns toeach of the N pieces of information such that the M scrambling patternsare repeated N/M times, so as to generate the N pieces of scrambledinformation.
 3. An information encoding apparatus according to claim 1,further comprising a first storage section for storing the N pieces ofscrambled information and the N parities in order to supply the N piecesof scrambled information with the N parities.
 4. An information encodingapparatus according to claim 1, further comprising a second storagesection for storing the M scrambling patterns.
 5. An informationencoding apparatus according to claim 1, wherein the encoded informationgeneration section is a division circuit.
 6. An information encodingapparatus according to claim 1, wherein the encoded informationgeneration section generates the N parities by erasure correction.
 7. Aninformation encoding apparatus according to claim 1, wherein N is 32 andM is
 1. 8. An information encoding method for encoding N pieces ofinformation, the information encoding method comprising the steps of:(a) generating M scrambling patterns (N>M≧1; where M and N are each aninteger); (b) applying, to each of the N pieces of information, onecorresponding scrambling pattern among the M scrambling patterns,thereby generating N pieces of scrambled information; and (c) supplyingthe N pieces of scrambled information with N parities, respectively,thereby generating encoded information; wherein each of at least one ofthe M scrambling patterns is applied to two or more of the N pieces ofinformation.
 9. An information encoding method according to claim 8,wherein the M is a divisor of N, and step (b) includes the step ofapplying one corresponding scrambling pattern among the M scramblingpatterns to each of the N pieces of information such that the Mscrambling patterns are repeated N/M times, thereby generating the Npieces of scrambled information.
 10. An information encoding methodaccording to claim 8, further comprising the step of storing the Npieces of scrambled information and the N parities in order to supplythe N pieces of scrambled information with the N parities.
 11. Aninformation encoding method according to claim 8, further comprising thestep of storing the M scrambling patterns.
 12. An information encodingmethod according to claim 8, wherein step (c) includes the step ofgenerating the N panties by division.
 13. An information encoding methodaccording to claim 8, wherein step (c) includes the step of generatingthe N panties by erasure correction.
 14. An information encoding methodaccording to claim 8, wherein N is 32 and M is
 1. 15. An informationre-encoding apparatus for re-encoding a plurality of pieces of firstencoded information into a plurality of pieces of second encodedinformation, wherein: the plurality of pieces of first encodedinformation include a plurality of first scrambled information scrambledby performing an arithmetic operation on a plurality of first scramblingpatterns with respect to a plurality of pieces of information by a firstarithmetic operation; the plurality of pieces of second encodedinformation include a plurality of pieces of second scrambledinformation scrambled by performing an arithmetic operation on aplurality of second scrambling patterns with respect to the plurality ofpieces of information by the first arithmetic operation, and a pluralityof second parities. the information re-encoding apparatus comprising: athird scrambling pattern generation section for performing an arithmeticoperation on the plurality of first scrambling patterns with respect tothe plurality of second scrambling patterns by a second arithmeticoperation, so as to generate a plurality of third scrambling patterns; ascrambled information generation section for performing an arithmeticoperation on the plurality of third scrambling patterns with respect tothe plurality of pieces of first scrambled information by the firstarithmetic operation, so as to generate the plurality of pieces ofsecond scrambled information; and an encoded information generationsection for supplying the plurality of pieces of second scrambledinformation with the plurality of second parities, so as to generate theplurality of pieces of second encoded information; wherein thearithmetic operations performed by the first arithmetic operation andthe second arithmetic operation fulfill (A∘B)●B=A, where ∘ represents afirst operator representing the arithmetic operation to be performed bythe first arithmetic operation, the ● represents a second operatorrepresenting the arithmetic operation to be performed by the secondarithmetic operation, and A and B each represent an arbitrary value. 16.An information re-encoding apparatus according to claim 15, furthercomprising a first storage section for storing the plurality of piecesof second scrambled information and the plurality of second parities inorder to supply the plurality of pieces of second scrambled informationwith the plurality of second parities.
 17. An information re-encodingapparatus according to claim 15, further comprising a second storagesection for storing the plurality of third scrambling patterns and theplurality of third parities.
 18. An information re-encoding apparatusaccording to claim 15, wherein: the plurality of pieces of first encodedinformation include a plurality of first parities; and the encodedinformation generation section includes: a third parity generationsection for generating a plurality of third parities in correspondencewith the plurality of third scrambling patterns; and a second paritygeneration section for performing an arithmetic operation on theplurality of third parities with respect to the plurality of firstparities by the first arithmetic operation, so as to generate theplurality of second parities.
 19. An information re-encoding apparatusaccording to claim 18, wherein the third parity generation section is adivision circuit.
 20. An information re-encoding apparatus according toclaim 18, wherein the third parity generation section generates theplurality of third parities by erasure correction.
 21. An informationre-encoding apparatus according to claim 18, wherein: the plurality ofpieces of first scrambled information are N pieces of information, theplurality of third scrambling patterns are M pieces of information(N>M≧1; M and N are each an integer; and M is a divisor of N), theplurality of first parities are N pieces of information, and theplurality of third parities are M pieces of information; the scrambledinformation generation section performs an arithmetic operation on onecorresponding third scrambling pattern among the plurality of thirdscrambling patterns with respect to each of the plurality of pieces offirst scrambled information by the first arithmetic operation, such thatthe plurality of third scrambling patterns are repeated N/M times, so asto generate N pieces of second scrambled information; and the secondparity generation section performs an arithmetic operation on onecorresponding third parity among the plurality of third parities withrespect to each of the plurality of first parities by the firstarithmetic operation, such that the plurality of third parities arerepeated N/M times, so as to generate N pieces of second parities. 22.An information re-encoding apparatus according to claim 21, wherein N is32 and M is
 2. 23. An information re-encoding method for re-encoding aplurality of pieces of first encoded information into a plurality ofpieces of second encoded information, wherein: the plurality of piecesof first encoded information include a plurality of first scrambledinformation scrambled by performing an arithmetic operation on aplurality of first scrambling patterns with respect to a plurality ofpieces of information by a first arithmetic operation; the plurality ofpieces of second encoded information include a plurality of pieces ofsecond scrambled information scrambled by performing an arithmeticoperation on a plurality of second scrambling patterns with respect tothe plurality of pieces of information by the first arithmeticoperation, and a plurality of second parities, the informationre-encoding method comprising the steps of: (a) performing an arithmeticoperation on the plurality of first scrambling patterns with respect tothe plurality of second scrambling patterns by a second arithmeticoperation, thereby generating a plurality of third scrambling patterns;(b) performing an arithmetic operation on the plurality of thirdscrambling patterns with respect to the plurality of pieces of firstscrambled information by the first arithmetic operation, therebygenerating the plurality of pieces of second scrambled information; and(c) supplying the plurality of pieces of second scrambled informationwith the plurality of second parities, thereby generating the pluralityof pieces of second encoded information; wherein the arithmeticoperations performed by the first arithmetic operation and the secondarithmetic operation fulfill (A∘B)●B=A, where ∘ represents a firstoperator representing the arithmetic operation to be performed by thefirst arithmetic operation, the ● represents a second operatorrepresenting the arithmetic operation to be performed by the secondarithmetic operation, and A and B each represent an arbitrary value. 24.An information re-encoding method according to claim 23, furthercomprising the step of storing the plurality of pieces of secondscrambled information and the plurality of second parities in order tosupply the plurality of pieces of second scrambled information with theplurality of second parities.
 25. An information re-encoding methodaccording to claim 23, further comprising the step of storing theplurality of third scrambling patterns and the plurality of thirdparities.
 26. An information re-encoding method according to claim 23,wherein: the plurality of pieces of first encoded information include aplurality of first parities; and step (c) includes the steps of: (c-1)generating a plurality of third parities in correspondence with theplurality of third scrambling patterns; and (c-2) performing anarithmetic operation on the plurality of third parities with respect tothe plurality of first parities by the first arithmetic operation,thereby generating the plurality of second parities.
 27. An informationre-encoding method according to claim 26, wherein step (c-1) includesthe step of generating the plurality of third parities by division. 28.An information re-encoding method according to claim 26, wherein step(c-1) includes the step of generating the plurality of third parities byerasure correction.
 29. An information re-encoding method according toclaim 26, wherein: the plurality of pieces of first scrambledinformation are N pieces of information, the plurality of thirdscrambling patterns are M pieces of information (N>M≧1; M and N are eachan integer; and M is a divisor of N), the plurality of first paritiesare N pieces of information, and the plurality of third parities are Mpieces of information; step (b) includes the step of performing anarithmetic operation on one corresponding third scrambling pattern amongthe plurality of third scrambling patterns with respect to each of theplurality of pieces of first scrambled information by the firstarithmetic operation, such that the plurality of third scramblingpatterns are repeated N/M times, thereby generating N pieces of secondscrambled information; and step (c-2) includes the step of performing anarithmetic operation on one corresponding third parity among theplurality of third parities with respect to each of the plurality offirst parities by the first arithmetic operation, such that theplurality of third parities are repeated N/M times, thereby generating Npieces of second parities.
 30. An information re-encoding methodaccording to claim 29, wherein N is 32 and M is 2.